The present invention relates to fluid pumps and the electric motors which may be used to drive them. In particular, the present invention relates to high efficiency compact fluid pumps which may be used to process a multiphase fluid.
Electric pump assemblies are used in a wide variety of industrial practices including the transport of fluids over long distances in pipelines, in wellbore applications for pumping production fluids, such as water or petroleum; and in chemical synthesis and processing applications. Electric pump assemblies used in industrial practice typically include, among other components, a pumping section that provides for the pumping of high volumes of fluid. A typical electric pump utilizes a combination of diffusers and impellers, together referred to as pump stages, for pumping fluids. During operation, the impellers are configured to rotate adjacent to fixed diffusers. Typically, the pumping section is coupled to an electric motor which provides mechanical energy to the pumping section by means of a rotary shaft coupled to the motor. A typical electric motor configured to drive the pumping section comprises an outer stator disposed around a torque-producing complement of an inner rotor. This necessarily limits both the size of the rotor and options for its mechanical coupling to the pumping section.
There remains a need to increase the utility of electric pump assemblies by making them more compact and more powerful. Accordingly, it is desired to provide electric pump assemblies which provide greater flexibility by being more compact and powerful relative to conventional electric pump assemblies.